Rizzarelli Paola, La Carta Stefania, Mirabella Emanuele Francesco, Rapisarda Marco, Impallomeni Giuseppe
Istituto per i Polimeri, Compositi e Biomateriali, Consiglio Nazionale delle Ricerche, Via Paolo Gaifami 18, 95126 Catania, Italy.
STMicroelectronics Srl, Stradale Primosole, 50, 95121 Catania, Italy.
Polymers (Basel). 2022 Apr 7;14(8):1500. doi: 10.3390/polym14081500.
Biodegradable and potentially biobased polyesteramide oligomers (PEA-Pro), obtained from melt condensation of sebacic acid and 3-amino-1-propanol, were characterized by nuclear magnetic resonance (NMR), matrix assisted laser desorption/ionization-time of flight/time of flight-mass spectrometry/mass spectrometry (MALDI-TOF/TOF-MS/MS), thermogravimetric analysis (TGA), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). NMR analysis showed the presence of hydroxyl and amino terminal groups as well as carboxylic groups of the sebacate moiety. Hydroxyl and carboxyl termination had the same abundance, while the amine termination was 2.7-times less frequent. Information regarding the fragmentation pathways and ester/amide bond sequences was obtained by MALDI-TOF/TOF-MS/MS analysis performed on sodiated adducts of cyclic species and linear oligomers. Different end groups did not influence the observed fragmentation. Three fragmentation pathways were recognized. The β-hydrogen-transfer rearrangement, which leads to the selective scission of the -O-CH- bonds, was the main mechanism. Abundant product ions originating from -CH-CH- (β-γ) bond cleavage in the sebacate moiety and less abundant ions formed by -O-CO- cleavages were also detected. TGA showed a major weight loss (74%) at 381 °C and a second degradation step (22% weight loss) at 447 °C. Py-GC/MS performed in the temperature range of 350-400 °C displayed partial similarity between the degradation products and the main fragments detected in the MALDI-TOF/TOF-MS/MS experiments. Degradation products derived from amide bonds were related to the formation of CN groups, in agreement with the literature.
通过癸二酸与3-氨基-1-丙醇的熔融缩聚反应制得的可生物降解且可能基于生物基的聚酯酰胺低聚物（PEA-Pro），采用核磁共振（NMR）、基质辅助激光解吸/电离飞行时间/飞行时间质谱/质谱（MALDI-TOF/TOF-MS/MS）、热重分析（TGA）以及热解气相色谱/质谱（Py-GC/MS）进行了表征。NMR分析表明存在羟基和氨基端基以及癸二酸酯部分的羧基。羟基和羧基封端具有相同的丰度，而胺封端的频率则低2.7倍。通过对环状物种和线性低聚物的钠加合物进行MALDI-TOF/TOF-MS/MS分析，获得了有关裂解途径以及酯/酰胺键序列的信息。不同的端基并未影响观察到的裂解。识别出了三种裂解途径。导致-O-CH-键选择性断裂的β-氢转移重排是主要机制。还检测到了源自癸二酸酯部分中-CH-CH-（β-γ）键裂解的大量产物离子以及由-O-CO-裂解形成的较少丰度的离子。TGA显示在381°C时出现主要失重（74%），在447°C时出现第二个降解步骤（失重22%）。在350 - 400°C温度范围内进行的Py-GC/MS显示降解产物与MALDI-TOF/TOF-MS/MS实验中检测到的主要碎片之间存在部分相似性。源自酰胺键的降解产物与CN基团的形成有关，这与文献一致。
